For the numerical analysis of the levitation of a rapidly running structure, such as a tape for a video tape recorder, a difference method is currently used. In this case, however, division of the analyzed domain of the object model to be analyzed into elements is confined to that of an orthogonal lattice, due to the inherence of the numerical analysis.
As for the construction of the analyzer, a known analyzer is shown in FIG. 3, has data input part 4, fluid analysis part 5 to compute the pressure of an air film, structural analysis part 6 to compute the displacement of a video tape, convergence judging part 7, and result output part 8. The levitation of the video tape is analyzed by alternately iterating fluid analysis and structure analysis to obtain a convergence solution.
The function of a conventional levitation analyzer having the construction described above is explained as follows. First, data relating to the geometrical shape of the analyzed domain of analyzed object model, the physical characteristics of the air, and the physical characteristics of the tape are entered at data input part 4. Based on this input data, fluid analysis part 5 solves a modified Reynolds equation on the air film to obtain the pressure acting on the tape. Then, at structural analysis part 6 from both the information on the pressure obtained at the fluid analysis part 5, and the data entered at data input part 4, an equation of motion on the tape is solved and the displacement of the video tape by the pressure of the air film is obtained. The output from the structural analysis part 6 is returned from the convergence judging part 7 to the input of the fluid analysis part 5, and analysis is again carried out, comparing the results of iterated computing with the former result. Iteration of the computing occurs until no difference is observed on the displacement of the tape, i.e. the convergence is judged by the convergence judging part 7. In such a manner, computing is iterated until the convergence is judged by the convergence judging part 7. The results as judged by the convergence judging part 7 are put out as various data such as either the deforming state and stress distribution of the tape or the pressure distribution of the air film.
A calculating process, such as described above, however, needs long computing time before the calculation converges. This is because the fluid analysis in the fluid analysis part and the structural analysis in the structural analysis part are independently carried out resulting in computation being iterated many times.
Also, analysis information of high accuracy was not obtained, since the difference method, of which the analyzing object was confined to an orthogonal lattice only, could not make an exact model of the cylinder or the head of the tape recorder (having, in fact, various curved surface).